> "The Child is father of the Man; / And I could wish my days to be / Bound each to each by natural piety."
Here, the speaker is expressing a deep longing for the innocence and wonder of childhood to stay with him throughout his life. He wishes for his days to be connected by a sense of "natural piety," meaning a reverence for the natural world and a deep appreciation for the simple things in life, just like a child possesses.
The speaker doesn't say "let me die," but he does express a sense of melancholy about the loss of that childlike wonder as he ages. The idea of "natural piety" being lost, perhaps replaced by the cynicism and jadedness of adulthood, could be interpreted as a form of "death" to the spirit.
It's important to remember that the poem is about the speaker's personal experience and perspective. It's not a call to literally die, but rather a lament for the loss of something precious and the hope that it can be regained or maintained throughout life.